Research On New Generation Of Ultra High Speed Wlan Energy Efficiency Transmission Techniques

As all kinds of smart devices and data services grow explosively, the demand of higher data rate in WLAN becomes stronger. Millimeter wave band which has huge swathes of available spectrum has been paid much attention to struggle with the scarcity of sub-6GHz spectrum. At the same time, the IEEE 802.11 aj (45GHz) standardization which runs on Chinese millimeter wave band is carrying on smoothly. However, with the increasing of WLAN users and popularization of green communication, power save has already become a critical issue in the WLAN design process. Based on power save mechanisms in the WLAN, the thesis studys energy efficiency communication techniques suitable for the IEEE 802.11aj (45GHz) system. The main work are as follows:1. The Transmit Opportunity Power Save (TXOP PS) mechanism suitable for IEEE 802.11 aj (45GHz) system is proposed. Based on the knowledge of power save mechanisms in WLAN and the characteristics of IEEE 802.11 aj (45GHz) system, applying TXOP PS mode in IEEE 802.11 aj (45GHz) system is proposed to allow stations that don't need to receive in the TXOP to enter Doze state. Seven conditions one of which the station in TXOP PS mode meets to enter Doze state are listed. The simulation results show that the stations that don't need to receive in the TXOP may consume less energy if TXOP PS mode is adopted.2. An enhanced Power-Save Multi-Poll (PSMP) mechanism applying multi-user transmission into PSMP downlink is proposed to improve the conventional PSMP mechanism which only supports multicast frame and single user unicast frame transmission. At the same time, a novel PSMP station information field is designed to improve the conventional PSMP frame. The simulation results show that energy consumption is greatly decreased in PSMP mechanism compared to Point Coordination Funtion (PCF) and the enhanced PSMP mechanism performs better than conventional PSMP in the aspect of energy conservation and energy efficiency.3. An improved dynamic bandwidth mechanism to be suitable for IEEE 802.11 aj (45GHz) system is proposed. Dynamic bandwidth subfield of Signal (SIG) field and the ZCZ permutation symbol of the Channel Estimate Field (CEF) indicate dynamic bandwidth and bandwidth information, respectively. Simulation results show that when the responder's secondary channel exists interference, the initiator adopting dynamic bandwidth mechanism consumes less energy to send this frame.4. A station-to-station (S2S) communication scheme based on hidden node pairs is proposed so that multiple pairs of hidden nodes can communicate during the same duration. One S2S announcement frame is designed to realize the S2S mechanism. Moreover, adding S2S communication scheme to the TXOP PS mode conditions one of which stations meet to enter Doze state is proposed to further save energy.